1. Field of the Invention
This invention relates generally to trailers and, more particularly to gooseneck trailers employed to move heavy equipment. In one aspect it relates to an improved linkage assembly for use in combination with a forward gooseneck member to form the folding gooseneck. In yet another aspect, it relates to an improved sliding link folding gooseneck assembly having improved capabilities for use as a loading ramp for a trailer when the folding gooseneck assembly is in an unfolded position.
2. Description of the Prior Art
Heretofore trailers, such as lowbed type trailers, have been used to transport heavy equipment from one construction site to another. However, problems of loading heavy equipment on the trailer have often created many difficulties.
In attempts to solve equipment loading problems, the prior art has utilized folding gooseneck trailers, portable loading ramps, or rear-end loading ramps secured to the trailer itself. When employing a folding gooseneck trailer to transport the equipment, the gooseneck is unfolded and extended to the ground so that it may serve as a cargo ramp. Extension into the ramp configuration is made possible by a rigid parallelogram linkage in the gooseneck. However, the nature of this linkage is such that, given the geometrical relations between the trailer bed, the gooseneck, and the ground, it is generally not possible to extend the gooseneck such that a uniformly flat ramp is provided for on-loading and off-loading with consistency. In the area of attachment of the linkage and the upper gooseneck member there will at times be a "hump" in the loading surface which causes the linkage to suffer undue stress during loading and unloading of the trailer. Further, difficulties are at times encountered in moving heavy equipment over the resulting "hump".
The use of portable loading ramps has suffered from several deficiencies, namely the necessity of transporting the portable ramp from site to site along with the heavy equipment thus reducing the payload which the trailer is capable of carrying; or, the portable loading ramp must be moved by a separate vehicle which is expensive, time consuming and, many times, not available when needed. In addition, safety factors are often lacking in the use of such portable ramps due to slippage of the ramp and the like.
Another means for loading heavy equipment on trailers used in the prior art consists of securing a loading ramp to the rear end portion of the trailer. This allows one to lower the ramp and thereafter drive the equipment up onto the bed of the trailer. However, such equipment is often bulky in nature, complicated in construction, and substantially reduces the payload of equipment which the trailer can transport from site to site.
Thus, none of the prior art ramp assemblies have fully met the requirement of a safe, economical, durable, light-weight loading means for loading heavy equipment onto trailers. New and useful loading techniques and apparatus are constantly being sought which do not suffer from the disadvantages of the prior art devices. Further, such devices should be economical to manufacture, durable in construction, relatively maintenance free and be so designed and constructed to become a part of the trailer without substantially reducing the payload of equipment which the trailer is designed to carry.
Therefore, an object of the present invention is to provide an improved loading ramp for a trailer which is an integral part of the trailer but does not substantially reduce the equipment carrying capabilities of the trailer.
Another object of the invention is to provide an improved loading ramp which is durable in construction, economical to manufacture, substantially maintenance free and does not suffer from the disadvantages of other prior art devices.
These and other objects, advantages, and features of the present invention will become apparent to those skilled in the art from a reading of the following detailed description when read in conjunction with the accompanying drawings which illustrate the invention.